Production of acetone



- Patented Apr. 22, 1930 PATET OFFICE LEO SCHLECHT, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNOR TO I. G. FABIBENINDUSTRIE AKTIENGESELLSGHAET, 0F FRANKFORT-ON-THE-MAIN, GER- MANY, A CORPORATION OF GERMANY PRODUCTION OF ACETONIQ 30 Drawing. Application filed November 23, 1928, Serial No. 321,522,

In the application for Patent Ser. No. 304,834, filed September 8th, 1928, I have described a process for the production of acetone from acct lens and steam at an elevated temperature y means of a catalyst, the time of contact of the gases being kept longer than is employed for the production of acetaldehyde,

the said catalysts containing metals, or compounds of the same, the acetates of which deplomppise with the formation of acetone when eate I have now found that good yields of ace and tin or aluminium or heavy metals or compounds of the aforesaid metals or basic salts of such metals or any other com ounds thereof as become converted into oxi s, carbonates or acetates or basic salts during the reaction. Natural substances, such as calamine, beauxite and the like, or mixtures of the aforesaid substances may also be used.-

Suitable additions are, for example, vanadium pentoxid, manganese dioxid and chromium-thallium compounds and additions of one or more of the oxide of the alkaline earth metals or of aluminium or magnesium are particularly eflicient. Catalysts which may ave become sluggish or spent may be easily regenerated by an oxidizing treatment, for example, by heating in a current of moist air.

The most suitable temperature for the reaction depends on the nature of the catalyst employed and on the condition of its superficial area, and is, generally speaking, be tween 400 and 450 (1., but even at a lower temperature, such as about 350 C. or up to about 500 C. satisfying results can be obtained. The relative proportion of acetalde-e hyde to steam is preferably less than 1:1.

The steam may be partially or nearly completely replaced by oxygen, air or other gaseous mixtures containing oxygen.

and in Germany December 18, 1927.

In order to prevent polymerization and decomposition of the resulting acetone, the reaction mixture should be passed over the catalyst not too slowly. To prevent overheating in the reaction chamber, which would also lead to loss of acetone, the reaction compounds are preferably preheated, either separately or in admixture. Moreover, a good distribution of the heat in the reaction chamber can also be ensured by depositing the catalyst on carriers of materials which are good conductors of heat, such as aluminium rlngs.

The hot mixture of gas and vapor issuing w from the reaction chamber is passed, for example, through a column still, this treatment separating the acetone from surplus water and also from carbon dioxid and hydrogen.

The following examples will further illustrate the nature of the said invention which,

however, is not limited thereto. The parts are I by weight.

Example 1 -A mixture of 1 part of acetaldehyde and 4 parts of steam is passed through an aluminium tube which is charged with zinc oxid heated to 400 C. When the vapor mixture is passed at the rate of about 250 liters per hour, for 1 liter of catalyst, the yield of acetone obtained is more than per cent of the amount 1 calculated equation QCI LGHO H O- CH3COCH CO 2H in accordance with the The gas remaining after the condensation of the vapors of acetone and water contains, on the average, 22 per cent of carbon dioxid and about 70 per cent of h drogen, together with small amounts of car on monoxid and hydrocarbons, and may be further employed for various purposes after, if so desired, th

elimination of the carbon dioxid.

Emmple 2 An aqueous solution of 30 per cent aqueous acetaldehyde is vaporized in a preheater and the vaporous mixture is passedv at about 410 C. over a catalyst prepared by mixing preci itated aluminium oxid and zinc oxid. n

- pound of zinc.

, acetone-W 1 passing the vapors of 0.3 liter of the aforesaid solution over 1 liter of catalyst per hour, 93 per cent of the aldehyde is converted into Example 3 Under the conditions described in the foregoing example, but by employing a catalyst consisting of a mixture of aluminium rings and zinc carbonate a yield of 95 per cent of acetone calculated on the amount of aldehyde employed is obtained.

What I claim is: Y

1. Theprocess of producing acetone, which comprises passing acetaldehyde together with steam at-a temperature between about 350 and 500 C. over a catalyst containing zinc.

2. The process of producing acetone, which comprises passing acetaldehyde together with steam at a temperature between about 350 and 500 C. over a catalyst containing zinc and another metal the acetate of which decomposes under the said conditions.

3. The process of producing acetone,which comprises passing acetaldehyde together with steam at a temperature between about 350 and 500 C. overa catalyst comprising a com- 4. The process of producing acetone, which comprises passing acetaldehyde together with steam at a temperature between about 350 and 500 C. over a catalyst comprising a compound of zinc and another'metal the acetate of which decomposes under the said conditions. 7

5. The process of producing acetone, which comprises passing acetaldehyde together with steam at a temperature between about 350 and 500 C. over a catalyst comprising a compound of zinc and an oxid of an element selected from the group consisting of the albeweenabout 400and 450 C. over a catalyst comprising a compound of zinc.

10. The process of producing acetone,

which comprises passing a mixture of acetal dehyde and a quantity of steam greater than that- 'of the 'acetaldehyde employed at'about a catalyst comprising z nc oxid and a compound of another metal the acetate of which decomposes under the said'cohditions.

13. The process of producing acetone,

which comprises passing a mixture of acetaldehyde and a quantity of steam greater than that of the acetaldehyde employed at a tem- 'perature between about 350 and 500 C. over a catalyst comprising zinc oxid and aluminium oxid. V

14. The process of producing acetone, which comprises passing acetaldehyde together with a gaseous'mixture comprising steam and oxygen at a temperature between about 350 and 500 C. over a catalyst containing, zinc.

In testimony whereof I have hereunto set my hand.

- LEO SGHLEGHT.

I kaline earth metals, aluminium and magnesium. c

6. The process of producing acetone, which comprises passing acetaldehyde together with steam at a temperature between about v400 and 450 C. over a catalyst comprising zinc oxid. 4

7. The process of producing acetone, which comprises passing acetaldehyde together with steam at a temperature between about 400 and 450 C. over a catalyst comprising zinc oxid and another metal the acetate of which decomposes under'the said conditions;

8. The process of producing acetone, which comprisespassing a mixture of acetaldehyde and a quantity of steam greater than that of the acetaldehyde employed at a temperature between about 350 and 500 C. over a catalyst containing zinc.

9. The process of producing acetone, which comprisespassing a mixture of acetaldehyde and a quantity of steam greater than that of the acetaldehyde employed at a temperature 

